Team Mitt has certainly done its best during the campaign to push faith itself, rather than the particulars of the Church, leaving their candidate to emphasise “shared values” over denomination.

Speaking to the Huffington Post UK, Dr Uta Balbier, the Director of the Institute of North American studies at King’s College London, argued that Romney has been successful to this end, and has “established himself as a person of faith in the eyes of the American voters”. As such, Romney has managed to make “the general perception of his faith more important than his belonging to the LDS church”. By emphasising Mormonism into just another branch of Christianity, Romney has neatly sidestepped the issue.

One can speculate whether the YouTube clip will undo Romney’s clever evasions come Tuesday night. However, that the former Governor of Massachusetts was even able to secure the Republican nomination speaks well of a religious pluralism that the US is rarely given credit for (albeit a win aided by a paucity of credible candidates from the dominant Evangelical wing of the GOP, as well as Romney’s large bank balance).

Should a Mormon beat Obama, would that not represent a victory for diversity of American society, an openness already emphasised in the election of an African American in 2008 and a Catholic in 1960? Perhaps, though some will no doubt see it as a testament to Republicans voters’ willingness to overlook Romney’s Mormonism (or at least to have their concerns subsumed by an often rabid desire to see the incumbent serve only a single term).

But why should Romney’s religion be so controversial, especially as the LDS, a 19th century off-shoot of Christian Protestantism, represents a modern American success story, with the religion currently boasting more than 13 million members worldwide?

The faith certainly has a chequered past, particularly in the practice of polygamy. Yet polygamy – the one certain fact everyone knows about Mormonism – was left behind by the main church more than a century ago and is now only practised by some of the movement’s more fundamentalist sects. As Romney noted in a recent 60 Minutes episode: “I can’t think of anything more awful.”

Since the days of its birth, the Church has undergone gradual change, with many of its rougher foundational edges softened by schism and secularisation, resulting in the seemingly more “benign” variant practised by Romney and his contemporaries today (although it is important to note that it wasn’t until the ’70s that the Church ended its prohibition on non–white members).

The LDS has its odd beliefs – the Garden of Eden was geographically in the US and that Christ will rule from Missouri upon his return – but Mormonism is hardly the only religion to hold bizarre revelations (the evangelical rapture or the return of the 12th Imam are no less inexplicable).

That’s not to say the modern LDS church is a bastion of transparency and openness – secrecy and obfuscation remain, particularly when dealing with the outside world. Non-members aren’t allowed into Mormon temples, while members are threatened with excommunication for discussing the faith’s rituals or theology.

Again, witness Romney’s unease when pushed to discuss the finer points of his faith or the rarity by which elders in the Church offer insight (the European LDS church was contacted for this article but would not comment due to “political neutrality”).

Yet secrecy alone is unlikely to be enough for one-in-five Americans to say they would not vote a Mormon for President as highlighted in a recent Gallup poll.

In a recent interview with CNN, Russell Ballard, an Apostle in the LDS, said it would be “misguided” if a politician tried to proselytize his religion while in office. Yet herein sits the problem for Romney: there’s the suspicion that a Mormon president would take direction from his Church rather than his office, echoing the anti-Catholic concerns surrounding Kennedy’s campaign in 1960 when critics argued that the Pope would be able to exert ‘foreign’ influence on the Camelot coterie.

There is also the Mormon belief that America is divinely blessed, so much so that church members profess that Christ actually visited the US two millennia ago, a notion heretical to Christians of other stripes. This has led many Americans, particularly conservative evangelicals, to dismiss the LDS as a cult, albeit based on the hypercritical notion their brand of Christianity is somehow lent authenticity due to its antiquity.

For Balbier, two things have helped Romney reduce Christian concerns over his faith: “His choice of the ultra-conservative Catholic Paul Ryan made the ticket more appealing for conservative Christian voters and the fact that Billy Graham, one of the most influential Christian evangelists in the US offered his endorsement.”

So if Romney wins, is it a victory for religious pluralism in the US?

“Religious pluralism [in the US] is functioning to an impressive degree,” said Balbier, “but from a European perspective, the acid test would be the presidential campaign of a Muslim candidate”.

Perhaps a Muslim candidate in four years time (hopefully running against a Trump-Palin ticket), but whatever happens on Tuesday night, the 2012 election has added yet another layer to the increasingly complex and often paradoxical relationship between a nation founded on principles designed to limit religion, and its citizens’ ardent desire to practise it.